Eddy Currents ‘An Issue’ With the E-Cat

This is only the briefest snippet of information, but perhaps this might give us a clue as to one thing that might be causing problems for Andrea Rossi and his team with the E-Cat plant — or maybe the E-Cat X (or both)

A reader on the Journal of Nuclear Physics named Rick asked Rossi: “Did you have to deal with the problem of the Eddy currents?”

Rossi responded simply: “Yes, it is an issue.”

Here’s a definition of Eddy Currents from Wikipedia:

Eddy currents (also called Foucault currents) are loops of electric current induced within conductors by a changing magnetic field in the conductor, due to Faraday’s law of induction. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field.

There is no detail in this brief Q&A, and I am very much a novice when it comes to understanding electronic issue, but I do wonder if there are electromagnetic pulses involved in the stimulation of the E-Cat, perhaps one consequence is the production of Eddy currents that provide some kind of unwanted interference that causes problems with the E-Cats.

It is clear that the varying magnetic fields cause the eddy currents. The question is what problems do these currents cause in the operation of the reactor. It depends on the dH/dt of the magnetic field. The shorter the magnetic field change, the higher the frequency of the induced currents. Obviously is the current size also dependent of the strength of the field (H) and the time (t).
If strong fields do not change quickly, they may induce voltages (and currents) in the heating coil. Short local changes of the field may more easily induce voltages and currents in the temperature sensors. Both can cause serious damage to both the heating coil thyristor/IGBT/Triac controllers and the sensor electronics. Besides that, it will lead to wrong temperature measurements. However, I would not call induction of currents/voltages in the heating coil, ‘eddy currents’ but EM disturbances. Eddy currents run locally in solid conducting materials (e.g. metals). They can overheat a pipe (that e.g.surrounds the reactor) or a nearby plate used for screening. Induction heating is indeed the best example for an eddy current based application. I do not see an eddy current cause problems with an Ecat, unless it heats things in the neighbourhood unintendedly, like the penny in Andrea Rossy’s wallet ;-).

Agaricus

The presence of eddy currents intense enough to present problems further confirms the existence of powerful varying magnetic fields arising either from EM stimulation, or as a function of reactor operation (or both). The eddy currents may arise within casings or other metal components, but the most likely cause of concern might be the nickel nanoparticles themselves.

When fine ferromagnetic powders are subjected to intense, varying EM fields, as the field rises each particle becomes a minute electromagnet, and when the external field falls, the field surrounding the particle collapses and converts to electron flow. In practice, and especially if the particles are non-static, this can result in nanoscale arcing within the metal dust, which in turn generates heat and may even cause sintering of particles if the energies concerned are high enough.

Warthog

“Problematic” eddy currents pretty much have to arise from fluctuations in the LENR process. “EM stimulation” would be whatever driving field is used, and could hardly be termed “problematic”, as they are inherent in the electrodynamics of the external heater, however driven (except for DC drive, of course).

Also, “EM stimulation” cannot be the sole driving force for the LENR effect, as Pons and Fleischmann’s electrolytic devices used DC, although other researchers (SPAWAR) have examined the effect of external fields applied to electrolytic LENR cells.

If the mechanism that produces the LENR effect is based on the production intense magnetic fields, control of the free electrons effected by those magnetic fields could well be an engineering issue. DGT reported that their system disbled the phone system in the building in which they were in and it also casued National instraments a lot of problems during their instrumentation of for the ICCF demo.

There are certain kinds of magnetic fields that MuMetal cannot shield.

Varying magnetic fields generate eddy currents that act to cancel the applied magnetic field. (The conductor does not respond to static magnetic fields unless the conductor is moving relative to the magnetic field.) The result is that electromagnetic radiation is reflected from the surface of the conductor: internal fields stay inside, and external fields stay outside.

MWerner

Eddy currents in electrical machinery is typically seen as a loss in efficiency. Those currents can flow in things like frames, transformer cores and motor armatures. The result is typically the generation of heat. This was one of the argument points in the DC vs AC debate since Eddy currents are a result of varying magnetic fields.

http://www.lenrnews.eu/lenr-summary-for-policy-makers/ AlainCo

yes, eddy current are an issue (to check, manage, often not problematic) even for a pure electric heater.
His technology use triac-switched controller which create noticeable transient, and the eddy curent can create unexpected heating in some metals, and change the impedance of the component…